The present invention concerns a baler (commonly known as "round" baler) for forming cylindrical bales.
The baler is of a well-known general type and comprises a plurality of rollers, sets of bands or belts supported on the rollers and defining a bale-forming chamber. A cylindrical bale is formed in the chamber by driving the belts to impart a rolling action to an incoming crop (e.g., forage and hay) as the baler is driven through a crop-containing field. When the bale attains the desired diameter and has been bound, the rear gate of the baler which is stopped, is opened and the bale is discharged onto the ground. The formation of another bale by rolling up can then be commenced inside the press.
Some of the belt supporting rollers are carried by pivotally mounted tensioning arms or equivalent members in such a manner that the path or movement of the belts is modified during bale formation so as to enlarge the bale-forming chamber to acommodate the increasing bale diameter.
In one commercially available round baler, the bale is deposited on the ground behind the bale-forming chamber after the opening of the rear gate. The rear gate of the baler is mounted for pivotal movement about a transverse horizontal axis located towards the upper part thereof. Following bale ejection, it is necessary to move the baler forward before the rear gate can be closed. The forward movement cannot take place simultaneously with the picking up of the crop on the ground since the chamber of the baler is then open. Consequently, it is necessary to move the machine backwards for the discharge of the bale and then, the gate being open, to return it to the beginning of the swath. It is thus possible to close the gate without hitting the bale and to pick up the crop again at the beginning of the swath. Otherwise, there would be a resulting loss of the crop remaining on the ground each time a completely formed bale is ejected.
Certain solutions to this problem have been proposed. In U.S. Pat. No. 4,206,587, a round baler with a resiliently mounted transverse bar for rearwardly propelling a bale as it is discharged from the chamber of the baler is disclosed. With the action of the resiliently mounted bar, the bale is propelled with sufficient force that it will roll rearwardly of the baler a sufficient distance so that the discharge gate of the baler may be closed without moving the baler forwardly. Also, in U.S. Pat. Nos. 4,208,862 and 4,218,866, a round baler with a bale-forming chamber defined by a plurality of reversibly driven chains is disclosed. The chains are driven in a first direction during the bale-forming operation and then are automatically reversibly driven during the bale discharge operation to impart a rearwardly directed top spin to the bale as it is discharged from the bale-forming chamber. The top spin imposed on the bale as it is discharged carries the bale away from the baler a sufficient distance so that the baler does not have to be driven forwardly to permit the closing of the discharge gate. Both of these approaches present certain inherent disadvantages. Both approaches operate on the basis of providing a rearwardly directed top spin to the bale as it is discharged from the bale-forming chamber. Because the bales may weigh between 900 and 1000 kg the uncontrolled rearward motion of the bale could be dangerous to anyone in the vicinity of the baler. In addition, if the baling operation is taking place in a hilly area, the bale may roll down a hill which could be dangerous and could position the bale in a location from which it would be difficult to retrieve. Furthermore, because, with varying crop conditions, the weight of the bale may vary from one bale to the next during the baling operation, the amount of energy imparted to the bales may need to be varied from one bale to the next. With both the foregoing designs, such variation is not possible.
Accordingly, it is an object of this invention to provide an improved baler which overcomes the inconvenience of rearward and forward movement of the baler during a bale discharge operation.
Another object of the invention is to provide a baler with a bale discharge gate which provides a controlled rearward rolling action to the bale.
Another object of this invention is to provide a baler with a bale-forming chamber defined by a plurality of reversibly driven bale-forming members, such as belts, for driving in a first direction during the formation of the bale and for driving in a second direction responsive to the discharge of the bale to roll the bale away from the baler.